JPH0717451B2 - Water jet nozzle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Object of the Invention [Field of Industrial Application] The present invention relates to a water jet nozzle, and more particularly to a water jet nozzle formed of a titanium boride ceramics sintered body. is there.

[Prior Art] Conventionally, as this type of water jet nozzle, a nozzle formed by adding cobalt Co or the like to tungsten carbide WC and sintering it has been proposed.

[Problems to be solved] However, in the conventional water jet nozzle,
(I) Since cobalt Co was added to the tungsten carbide WC, pressurized water (that is, an average particle size of 200μ
Although abrasion resistance to water pressurized to 2000 to 4000 kg / cm ² containing about m of alumina powder and the like; the same applies hereafter) was slightly improved, the Vickers hardness and transverse strength were still small, resulting in abrasion. There is a drawback that can not be suppressed sufficiently,
As a result, (ii) it has a drawback that it cannot have a long service life.

Therefore, in order to solve these drawbacks, the present invention provides a water jet nozzle which is formed of a titanium boride ceramics sintered body to suppress wear when jetting pressurized water.

(2) Configuration of the Invention [Means for Solving Problems] Means for solving the problems provided by the present invention include: In the jet nozzle for water jet, a matrix layer formed by mixing and solid-dissolving boride of at least one metal selected from chromium Cr, nickel Ni, and molybdenum which are transition metals and titanium carbide is formed between titanium boride particles. A nozzle for water jet, characterized in that it is entirely formed of a titanium boride ceramics sintered body having a porosity of 5% or less.

[Operation] In the water jet nozzle according to the present invention, the matrix layer in which a boride of at least one metal selected from transition metals such as chromium Cr, nickel Ni, and molybdenum Mo and titanium carbide is mixed and solid-solved is formed. Since the whole is formed by a titanium boride ceramics sintered body having a porosity of 5% or less, which is arranged between titanium oxide particles,
(I) It has a function of sufficiently suppressing the abrasion accompanying the jetting of the pressurized water, and (ii) it has a function of achieving a long life.

[Examples] Next, the present invention will be specifically described with reference to the accompanying drawings.

FIG. 1 is a partial cross-sectional view showing an embodiment of a water jet nozzle according to the present invention, which is formed of a titanium boride ceramics sintered body as a whole.

FIG. 2 is a sectional view showing a usage state of the embodiment shown in FIG.

FIG. 3 is an enlarged sectional view showing the embodiment of FIG.

FIG. 4 is an optical micrograph showing the texture of the polished surface of the example of FIG. 1, showing the case of Example 4.

FIG. 5 is a scanning electron micrograph showing the structure of the fracture surface of the embodiment of FIG. 1, showing the case of the fourth embodiment.

FIG. 6 is an optical micrograph showing the texture of the etched surface of the embodiment of FIG. 1, showing the case of the fourth embodiment.

FIG. 7 is a scanning electron micrograph showing the texture of the etched surface of the embodiment of FIG. 1, showing the case of the fourth embodiment.

FIG. 8 is a scanning electron micrograph showing the structure of the surface of the nozzle hole portion subjected to the polishing treatment in FIG.
In this case, the part where the particles fall off during the polishing process is shown in black.

FIG. 9 is a copy of FIG. 8, in which the dropout portion of the particles during the polishing process is shown in black.

FIG. 10 is an X-ray intensity distribution chart showing the result of EPMA analysis, that is, electron probe microanalysis on the structure of the nozzle hole surface after the polishing treatment in FIG. It shows the case where it was done.

FIG. 11 (a) is an X-ray intensity distribution photograph showing the results of EPMA analysis, that is, electron probe microanalysis, on the texture of the surface subjected to polishing in FIG.
The figure shows the case where it is executed for almost the whole of the figure, and the portion corresponding to chrome is shown in black.

FIG. 11 (b) is an X-ray intensity distribution photograph showing the results of EPMA analysis, that is, electron probe microanalysis, on the texture of the polished surface of the embodiment of FIG.
The figure shows the case where it is executed for almost the whole of the figure, and the portion corresponding to titanium is shown in black.

FIG. 11 (c) is a duplicated drawing made by superimposing 11 (a) and (b), in which chromium is shown by a broken line and titanium is shown by a solid line.

FIG. 12 is a graph showing the result of the X-ray diffraction analysis executed for the nozzle hole portion of FIG.
In this case, the horizontal axis shows the X-ray diffraction angle and the vertical axis shows the X-ray diffraction intensity.

FIG. 13 is a scanning electron micrograph showing the structure of the fracture surface of the water jet nozzle shown as Comparative Example 1.

First, the configuration and operation of one embodiment of the water jet nozzle according to the present invention will be described in detail. Reference numeral 10 denotes a cylindrical water jet nozzle according to the present invention, which is entirely formed of a titanium boride ceramics sintered body. The water jet nozzle 10 has a nozzle hole 11 whose both ends are open. Nozzle hole 11
Is enlarged at one end thereof, so that the pressurized water can be easily received from the tip of the supply pipe (not shown) of the pressurized water.

A water jet nozzle ( 10) according to the present invention has a locking end surface (12) formed on a peripheral surface of an intermediate section and directed toward a tip section.
And a fixed end surface 13 formed by tapering around the rear end surface.

The water jet nozzle 10 according to the present invention is arranged in the central hole 14A of the nozzle holder 14, so that the locking end surface 12 thereof is locked to the locking step portion 14B of the central hole 14A, and the fixed end surface 13 thereof. Is pressed by a fixed end surface 15A formed by tapering around the opening of the tip of the fixing member 15. If desired, the nozzle holder 14 has a reinforcing member 16 arranged around the tip thereof. Here, it is desirable that the nozzle holder 14, the fixing member 15, and the reinforcing member 16 are made of an appropriate material such as cemented carbide.

When used, the nozzle holder 14 is attached to the tip end portion (not shown) of the pressurized water supply pipe of the water jet cutting device, and the pressurized water supplied from the supply pipe is supplied to the nozzle hole 11 through the central hole 15B of the fixing member 15. And is ejected toward the material to be cut (not shown) from the opening of its tip.

At this time, the water jet nozzle according to the present inventionTen
Is a transition metal such as chromium Cr, nickel Ni, molybdenum
Boride and carbonization of at least one metal selected from Mo
Titanium boride is used as the matrix layer mixed with titanium to form a solid solution.
A foil disposed between the particles and having a porosity of 5% or less.
Formed by titanium carbide ceramics sintered body
Therefore, the nozzle hole 11 should not be worn by the pressurized water.
It can be suppressed sufficiently.

The water jet nozzle 10 according to the present invention has titanium boride TiB ₂ particles 20 and a mesh-like bonding layer 30 for bonding the titanium boride TiB ₂ particles 20 in its structure.

The titanium boride TiB ₂ particles 20 have an average particle size of 0.5 to 10 μm and a maximum particle size of 12 μm, and particularly an average particle size of 0.5 to 3
It is preferable that the particle size is μm and the maximum particle size is 6 μm. Here, the basis for setting the average particle size of the titanium boride TiB ₂ particles 20 to 0.5 to 10 μm is (i) when the average particle size is less than 0.5 μm, the surface oxidation of the titanium boride TiB ₂ particles 20 becomes remarkable, In addition, the agglomeration between the titanium boride TiB ₂ particles 20 becomes remarkable, which significantly hinders the sintering of the titanium boride ceramics sintered body according to the present invention, that is, the water jet nozzle 10 , and (ii) the average particle size. If the diameter exceeds 10 μm, the driving force for sintering becomes small, and it becomes difficult to densify the water jet nozzle 10 according to the present invention, and the existing cracks are expanded in the titanium boride TiB ₂ particles 20 and the It is to reduce the strength of the water jet nozzle 10 according to the invention. In addition, the reason why the maximum particle size of the titanium boride TiB ₂ particles 20 is 12 μm is that if the maximum particle size exceeds 12 μm, it will be present as coarse particles in the water jet nozzle 10 according to the present invention. It is to prevent the water jet nozzle 10 according to the present invention from increasing in density or strength.

Titanium boride TiB ₂
TiB ₂ and boride of metal M described later, that is, metal boride MB,
A grain boundary phase 21 composed of a mixed solid solution phase with MB ₂ or M ₃ B is formed. As a result, the bonding force between the titanium boride TiB ₂ particles 20 and the bonding layer 30 is made sufficiently large, and as a result, the water jet nozzle according to the present invention.
10 strength etc. are secured.

The coupling layer 30 is made of at least one metal M selected from transition metals such as chromium Cr, nickel Ni, and molybdenum Mo (hereinafter,
Similarly) and _{TiB 2 + 2M + C → 2MB} + TiC or _{TiB 2 + M + C → MB} 2 + TiC or _{TiB 2 + 6M + C → 2M} 3 B + metal boride i.e. metal M generated by the reaction such as TiC between titanium boride TiB ₂ and carbon C This is a matrix layer in which boride MB, MB ₂ or M ₃ B, etc. and titanium carbide TiC are mixed and solid-solved, and voids are sufficiently removed. As a result, the bonding force between the titanium boride TiB ₂ particles 20 is made sufficiently large, and the porosity of the water jet nozzle 10 (that is, the value obtained by dividing the pore volume by the total volume) is 5% or less. As a result, the density and strength of the water jet nozzle 10 according to the present invention are secured. The reason why the pores are substantially removed from the bonding layer, that is, the matrix layer 30, is based on the particle size of boride of metal M, that is, metal boride MB, MB ₂ or M ₃ B, and the particle size of titanium carbide TiC. And are almost in agreement with each other, and they are in the form of homogeneously mixed and solid solution with each other.

Furthermore, the manufacturing procedure of one embodiment of the water jet nozzle according to the present invention will be described.

In the first step, a ceramic blend is prepared by blending titanium boride TiB ₂ powder with metal M powder and carbon C powder at an appropriate blending ratio.

That is, (i) the average particle size is 0.5 to 10 μm (preferably 0.5
Titanium boride TiB ₂ having a maximum particle size of 12 μm (preferably 6 μm) and a purity of 99% by weight or more, and (ii)
A metal M having an average particle size of 1 to 5 μm (preferably 1 to 3 μm) and a maximum particle size of 12 μm (preferably 6 μm), (ii
i) Specific surface area of 50 to 150 m ² / g (preferably 80 to 150 m ² / g)
With a purity of 99.9% by weight or more and an average particle size of 10 to 100 nm
Carbon (for example, carbon black) C having a maximum particle size of 150 nm (preferably 100 nm) (preferably 10 to 50 nm)
And are blended with each other to form a ceramic blend.
In the ceramic composition, titanium boride TiB ₂ is 11 to 99.9% by weight (especially 75 to 97.5% by weight) based on 0.1 to 89% by weight (especially 2.5 to 25.0% by weight is preferable) of a mixture of metal M and carbon C It is preferable if it is). Further, the mixing ratio of the metal M and the carbon C is 7: 0 by weight.
It is 1 to 10 (particularly preferably 7: 0.2 to 5).

Here, the reason why the purity of titanium boride TiB ₂ is 99% by weight or more is to avoid the adverse effect of impurities during sintering.

The reason why the average particle size of the metal M is 1 to 5 μm is as follows.
(I) If the average particle size is less than 1 μm, the surface oxidation of the metal M particles becomes remarkable, and the metal M particles are aggregated or the metal M particles are aggregated with titanium boride TiB ₂ particles or carbon C particles. Becomes remarkable, which significantly hinders the sintering of the water jet nozzle 10 according to the present invention,
Further, (ii) if the average particle size exceeds 5 μm, coarse particles are present in the grain boundary phase 21 formed near the grain boundary of the matrix layer 30 of the water jet nozzle 10 or the titanium boride TiB ₂ particles 20 according to the present invention. Exists to reduce the strength of the water jet nozzle 10 according to the present invention. The reason why the maximum particle size of the metal M is set to 12 μm is that if the maximum particle size exceeds 12 μm, the existing cracks in the metal M particles are enlarged and the strength of the water jet nozzle 10 according to the present invention is reduced. Especially.

The reason why the average particle size of carbon C is 10 to 100 nm is that (i) if the average particle size is less than 10 nm, the surface oxidation of the carbon C particles becomes remarkable and the aggregation between the carbon C particles becomes remarkable. Therefore, the sintering of the water jet nozzle 10 according to the present invention is significantly hindered, and (ii) if the average particle size exceeds 100 nm, the particles are present as coarse particles in the matrix layer 30. The purpose is to reduce the strength of the water jet nozzle 10 according to the present invention. The reason why the maximum particle size of carbon C is 150 nm is that if the maximum particle size exceeds 150 nm, the existing cracks in the carbon C particles or titanium carbide TiC particles generated by the reaction with titanium boride TiB ₂ This is to expand the existing cracks and reduce the strength of the water jet nozzle 10 according to the present invention.

Further grounds for the specific surface area of the carbon C is a 50 to 150 m ² / g is, (i) if the specific surface area is less than 50 m ² / g, titanium boride TiB ₂ become the carbon C particles is too large If the specific surface area exceeds 150 m ² / g, the carbon C particles will agglomerate with each other, and the titanium boride TiB ₂ and the metal M will not react with each other. The problem is that they cannot mix.

In the second step, the ceramic mixture is homogeneously mixed with an appropriate mixer to prepare a ceramic mixture.

In the third step, the ceramic mixture is put in an appropriate mold together with a binder (for example, polyvinyl alcohol), and then an appropriate pressure (for example, 100 to 800 kg / cm ²
Is applied to uniaxially apply pressure to produce a ceramic green compact.

In the fourth step, the ceramic green compact is subjected to a CIP process, that is, a normal temperature isostatic pressing process by applying an appropriate pressure (for example, a pressure of 800 to 3500 kg / cm ² ), to obtain a ceramic green body.

In the fifth step, the ceramic compact is placed in a non-oxidizing atmosphere (that is, a neutral or reducing atmosphere) such as a vacuum atmosphere (preferably having an atmospheric pressure of 10 ⁻³ Torr or less), an argon atmosphere or a hydrogen gas atmosphere. In a non-pressurized state or a pressurized state (applying a pressure of 100 to 500 kg / cm ² ), the ceramic is sintered at a temperature of 1500 to 2000 ° C (preferably 1700 to 1900 ° C) for an appropriate time. The body. The reason for the non-oxidizing atmosphere here is titanium.
It is to prevent Ti, boron B, metal M or carbon C from being oxidized.

In the sixth step, the ceramics sintered body is finished, that is, the inner surface of the nozzle hole 11 is mainly polished with a desired accuracy.

As described above, the water jet nozzle according to the present invention
10 are manufactured.

In addition, one embodiment of the water jet nozzle according to the present invention will be described by giving specific numerical values and the like for better understanding.

(Examples 1 to 7) Chromium Cr having an average particle size of 1 μm and a specific surface area of 135 m ² /
The average particle size was 3 μm and the maximum particle size was 6 μm, and the purity was 99% by weight, based on 2.5% by weight of the mixture prepared by changing the mixing ratio with carbon black C having a purity of 99% by weight in g.
100 parts of a ceramic compound prepared by mixing 97.5% by weight of titanium boride TiB ₂ is a plastic container with urethane balls and 300 parts of ethylene alcohol, and wet-mixed for 24 hours. A ceramic mixture was created.

The ceramic mixture was kept at a temperature of 60 ° C. for 10 hours to be thoroughly dried. After that, 100 parts of the ceramic mixture
It was housed in an appropriate mold together with 2 parts of polyvinyl alcohol as a binder, and a pressure of 300 kg / cm ² was applied to uniaxially press to obtain a ceramic green compact.

Ceramic green compacts are applied with a pressure of 3000 kg / cm ²
A ceramic compact was obtained by performing P treatment, that is, normal temperature isostatic pressing treatment.

The ceramic molded body was heated to a temperature of 1900 ° C. at a temperature rising rate of 15 ° C./min in an unpressurized argon atmosphere and maintained at a temperature of 1900 ° C. for 1 hour to obtain a ceramic sintered body. did.

The ceramics sintered body was subjected to finishing processing, that is, the inner surface of the nozzle hole 11 was polished to a desired accuracy.

The total length of the water jet nozzle 10 was 20 mm, the opening at the tip of the nozzle hole 11 had a diameter of 0.2 to 0.5 mm, and the wall thickness thereof was 2 to 5 mm.

The water jet nozzle 10 was as shown in FIG. 4 when the polished surface in the case of Example 4 (the same applies hereinafter) was photographically observed with an optical microscope.
That is, it was found that the recesses formed by the falling off of the titanium boride particles 20 were arranged in a dotted pattern, and the bonding layer 30 had no holes and was dense.

The water jet nozzle 10 was fractured by an appropriate force, and the fractured surface was photographically observed with a scanning electron microscope, and it was as shown in FIG. That is, it was found that intragranular fracture occurred in the titanium boride TiB ₂ particles 20, and the titanium boride TiB ₂ particles 20 were strongly bonded by the bonding layer 30. The bonding layer 30 is formed by X-ray diffraction analysis and EP
MA analysis revealed that the reaction between titanium boride TiB ₂ , chromium Cr and carbon black C TiB ₂ + 2Cr + C → 2CrB + TiC produced a mixed solid solution matrix layer of chromium boride CrB and titanium carbide TiC. Fig. To Fig. 12).

The water jet nozzle 10 was subjected to an etching treatment on its surface by immersing it in aqua regia heated to 60 ° C. for 3 minutes, and then photograph-observed with an optical microscope.
It was as shown in FIG. That is, it was found that the average particle size of the titanium boride TiB ₂ particles 20 was kept at _{2 to 4} μm by measuring the recesses formed by the titanium boride TiB ₂ particles 20 falling off by the etching treatment. In other words, it was found that the titanium boride TiB ₂ particles 20 did not grow much compared to the beginning. This is because chromium Cr and carbon black C cause a reaction of TiB ₂ + 2Cr + C → 2CrB ₂ + TiC during sintering, and the growth of titanium boride TiB ₂ particles 20 is suppressed. Also titanium boride TiB ₂ particles
It was also found by X-ray diffraction analysis and EPMA analysis that a grain boundary phase consisting of a mixed solid solution phase of titanium boride TiB ₂ and chromium boride CrB was formed in the vicinity of grain boundary 20 (8th). (See Figures to 12).

In addition, for the water jet nozzle 10 , wear resistance, Vickers hardness, bending strength, porosity, coefficient of thermal expansion,
When the thermal conductivity and the fracture toughness were measured, they were as shown in Table 1. Here, the wear resistance is indicated by using the weight n of the alumina powder having an average particle size of 20 μm used as projection particles and the wear weight m when the alumina powder is projected at a speed of 100 m / sec. (Same below).

The water jet nozzle 10 is inserted into the nozzle holder 14 and after the fixing member is arranged, the pressurized water supply pipe is attached,
Alumina powder with an average particle size of 200 μm as pressurized water
Water containing 0.2 g / cm ³ and pressurized to 3000 kg / cm ² was supplied and jetted from the nozzle hole 11 to the material to be cut. When continuously used in this state, the water jet nozzle 10 could be used for 7 days (see "Life" in Table 1).

(Examples 8 to 14) Examples 1 to 7 were repeated, except that titanium boride TiB ₂ was mixed in an amount of 95.0% by weight with respect to 5.0% by weight of the mixture of chromium Cr and carbon black C.

The water jet nozzle 10 was measured for wear resistance, Vickers hardness, bending strength, porosity, coefficient of thermal expansion, thermal conductivity, and fracture toughness. The results are shown in Table 1.

In addition, the life of the water jet nozzle 10 is
When measured in the same manner as in 7, the results are as shown in Table 1.

To (Example 15-21) mixture 7.5 wt% of chromium Cr and carbon black C, except that the blended titanium boride TiB ₂ only 92.5 wt%, was repeated Examples 1-7, respectively.

The water jet nozzle 10 was measured for wear resistance, Vickers hardness, bending strength, porosity, coefficient of thermal expansion, thermal conductivity, and fracture toughness. The results are shown in Table 1.

In addition, the life of the water jet nozzle 10 is
When measured in the same manner as in 7, the results are as shown in Table 1.

(Examples 22 to 28) Examples 1 to 7 were repeated, except that titanium boride TiB ₂ was mixed in an amount of 90.0% by weight with respect to 10.0% by weight of a mixture of chromium Cr and carbon black C.

The water jet nozzle 10 was measured for wear resistance, Vickers hardness, bending strength, porosity, coefficient of thermal expansion, thermal conductivity, and fracture toughness. The results are shown in Table 1.

In addition, the life of the water jet nozzle 10 is
When measured in the same manner as in 7, the results are as shown in Table 1.

Examples 29 to 35 Examples 1 to 7 were repeated except that titanium boride TiB ₂ was added in an amount of 87.5% by weight to 12.5% by weight of a mixture of chromium Cr and carbon black C.

The water jet nozzle 10 was measured for wear resistance, Vickers hardness, bending strength, porosity, coefficient of thermal expansion, thermal conductivity, and fracture toughness. The results are shown in Table 1.

In addition, the life of the water jet nozzle 10 is
When measured in the same manner as in 7, the results are as shown in Table 1.

(Examples 36 to 42) Examples 1 to 7 were repeated, except that 85.0% by weight of titanium boride TiB ₂ was added to 15.0% by weight of a mixture of chromium Cr and carbon black C.

The water jet nozzle 10 was measured for wear resistance, Vickers hardness, bending strength, porosity, coefficient of thermal expansion, thermal conductivity, and fracture toughness. The results are shown in Table 1.

In addition, the life of the water jet nozzle 10 is
When measured in the same manner as in 7, the results are as shown in Table 1.

(Examples 43 to 49) Examples 1 to 7 were repeated except that titanium boride TiB ₂ was added in an amount of 82.5% by weight to 17.5% by weight of a mixture of chromium Cr and carbon black C.

The water jet nozzle 10 was measured for wear resistance, Vickers hardness, bending strength, porosity, coefficient of thermal expansion, thermal conductivity, and fracture toughness. The results are shown in Table 1.

In addition, the life of the water jet nozzle 10 is
When measured in the same manner as in 7, the results are as shown in Table 1.

(Examples 50 to 56) Examples 1 to 7 were repeated except that 80.0% by weight of titanium boride TiB ₂ was added to 20.0% by weight of a mixture of chromium Cr and carbon black C.

The water jet nozzle 10 was measured for wear resistance, Vickers hardness, bending strength, porosity, coefficient of thermal expansion, thermal conductivity, and fracture toughness. The results are shown in Table 1.

In addition, the life of the water jet nozzle 10 is
When measured in the same manner as in 7, the results are as shown in Table 1.

(Examples 57 to 63) Examples 1 to 7 were repeated except that titanium boride TiB ₂ was added in an amount of 77.5% by weight to 22.5% by weight of a mixture of chromium Cr and carbon black C.

The water jet nozzle 10 was measured for wear resistance, Vickers hardness, bending strength, porosity, coefficient of thermal expansion, thermal conductivity, and fracture toughness. The results are shown in Table 1.

In addition, the life of the water jet nozzle 10 is
When measured in the same manner as in 7, the results are as shown in Table 1.

(Examples 64-70) Examples 1-7 were repeated except that titanium boride TiB ₂ was added in an amount of 75.0% by weight based on 25.0% by weight of a mixture of chromium Cr and carbon black C.

The water jet nozzle 10 was measured for wear resistance, Vickers hardness, bending strength, porosity, coefficient of thermal expansion, thermal conductivity, and fracture toughness. The results are shown in Table 1.

In addition, the life of the water jet nozzle 10 is
When measured in the same manner as in 7, the results are as shown in Table 1.

(Examples 71 to 77) Except that 7.5% by weight of a mixture of chromium Cr and carbon black C was mixed with 92.5% by weight of titanium boride TiB ₂ and the sintering temperature was 1500 ° C. Example 1
~ 7 was repeated.

With respect to the water jet nozzle 10 , abrasion resistance, Vickers hardness, bending strength, porosity, coefficient of thermal expansion, thermal conductivity and fracture toughness were measured, and the results are shown in Table 2.

In addition, the life of the water jet nozzle 10 is
When measured in the same manner as in 7, the results are as shown in Table 2.

(Examples 78 to 84) Except that 92.5% by weight of titanium boride TiB ₂ was added to 7.5% by weight of a mixture of chromium Cr and carbon black C, and the sintering temperature was set to 1600 ° C. Example 1
~ 7 was repeated.

With respect to the water jet nozzle 10 , abrasion resistance, Vickers hardness, bending strength, porosity, coefficient of thermal expansion, thermal conductivity and fracture toughness were measured, and the results are shown in Table 2.

In addition, the life of the water jet nozzle 10 is
When measured in the same manner as in 7, the results are as shown in Table 2.

(Examples 85 to 91) 92.5% by weight of titanium boride TiB ₂ was added to 7.5% by weight of a mixture of chromium Cr and carbon black C, and the sintering temperature was set to 1700 ° C. Example 1
~ 7 was repeated.

With respect to the water jet nozzle 10 , abrasion resistance, Vickers hardness, bending strength, porosity, coefficient of thermal expansion, thermal conductivity and fracture toughness were measured, and the results are shown in Table 2.

In addition, the life of the water jet nozzle 10 is
When measured in the same manner as in 7, the results are as shown in Table 2.

(Examples 92 to 98) 92.5% by weight of titanium boride TiB ₂ was added to 7.5% by weight of a mixture of chromium Cr and carbon black C, and the sintering temperature was 1800 ° C. Example 1
~ 7 was repeated.

With respect to the water jet nozzle 10 , abrasion resistance, Vickers hardness, bending strength, porosity, coefficient of thermal expansion, thermal conductivity and fracture toughness were measured, and the results are shown in Table 2.

In addition, the life of the water jet nozzle 10 is
When measured in the same manner as in 7, the results are as shown in Table 2.

Examples 99-105 Examples 15-21 were repeated, respectively.

The water jet nozzle 10 was measured for wear resistance, Vickers hardness, bending strength, porosity, coefficient of thermal expansion, thermal conductivity, and fracture toughness. The results are shown in Table 1.

In addition, the life of the water jet nozzle 10 is
When measured in the same manner as in 7, the results are as shown in Table 1.

Comparative Example 1 Examples 1-70 were repeated except that chromium Cr and carbon black C were removed from the ceramic formulation.

That is, 100 parts of titanium boride TiB ₂ having an average particle size of 3 μm, a maximum particle size of 6 μm, and a purity of 99% by weight is accommodated in an appropriate mold together with 2 parts of polyvinyl alcohol as a binder, and 300 kg / cm ² A ceramic green compact was created by applying pressure and uniaxially pressing.

The ceramic powder compact is CIPed by applying a pressure of 300 kg / cm ^2.
A ceramic molded body was obtained by performing a treatment, that is, a normal temperature isostatic pressing treatment.

The ceramic molded body was heated to a temperature of 1900 ° C. at a temperature rising rate of 15 ° C./min in an unpressurized argon atmosphere and maintained at a temperature of 1900 ° C. for 1 hour to obtain a ceramic sintered body. did.

The ceramics sintered body was subjected to finishing processing, that is, the inner surface of the nozzle hole was polished to a desired accuracy.

The water jet nozzle was fractured by an appropriate force, and the fractured surface was photographically observed with a scanning electron microscope, and it was as shown in FIG. Ie titanium boride
It was found that intergranular fracture of TiB ₂ particles occurred predominantly, and the bond between titanium boride TiB ₂ particles was not so strong.

In addition, the water jet nozzle has wear resistance,
Vickers hardness, flexural strength, porosity, coefficient of thermal expansion, thermal conductivity and fracture toughness were measured and found to be 1st, respectively.
It was as shown in the table.

Further, the life of the water jet nozzle is about 1 to 7
The measurement was carried out in the same manner as above, and it was as shown in Table 1.

Comparative Example 2 Examples 1-7 were repeated except that carbon black C was removed from the ceramic formulation.

The wear resistance, Vickers hardness, bending strength, porosity, coefficient of thermal expansion, thermal conductivity, and fracture toughness of the water jet nozzle were measured and found to be as shown in Table 1.

Further, the life of the water jet nozzle is about 1 to 7
The measurement was carried out in the same manner as above, and it was as shown in Table 1.

Comparative Example 3 Examples 8-14 were repeated except that carbon black C was removed from the ceramic formulation.

The wear resistance, Vickers hardness, bending strength, porosity, coefficient of thermal expansion, thermal conductivity, and fracture toughness of the water jet nozzle were measured and found to be as shown in Table 1.

Further, the life of the water jet nozzle is about 1 to 7
The measurement was carried out in the same manner as above, and it was as shown in Table 1.

Comparative Example 4 Examples 15-21 were repeated except that carbon black C was removed from the ceramic formulation.

The wear resistance, Vickers hardness, bending strength, porosity, coefficient of thermal expansion, thermal conductivity, and fracture toughness of the water jet nozzle were measured and found to be as shown in Table 1.

Further, the life of the water jet nozzle is about 1 to 7
The measurement was carried out in the same manner as above, and it was as shown in Table 1.

Comparative Example 5 Examples 22-28 were repeated except that carbon black C was removed from the ceramic formulation.

The wear resistance, Vickers hardness, bending strength, porosity, coefficient of thermal expansion, thermal conductivity, and fracture toughness of the water jet nozzle were measured and found to be as shown in Table 1.

Further, the life of the water jet nozzle is about 1 to 7
The measurement was carried out in the same manner as above, and it was as shown in Table 1.

Comparative Example 6 Examples 29-35 were repeated except that carbon black C was removed from the ceramic formulation.

The wear resistance, Vickers hardness, bending strength, porosity, coefficient of thermal expansion, thermal conductivity, and fracture toughness of the water jet nozzle were measured and found to be as shown in Table 1.

Further, the life of the water jet nozzle is about 1 to 7
The measurement was carried out in the same manner as above, and it was as shown in Table 1.

Comparative Example 7 Examples 36-42 were repeated except that the carbon black C was removed from the ceramic formulation.

The wear resistance, Vickers hardness, bending strength, porosity, coefficient of thermal expansion, thermal conductivity, and fracture toughness of the water jet nozzle were measured and found to be as shown in Table 1.

Further, the life of the water jet nozzle is about 1 to 7
The measurement was carried out in the same manner as above, and it was as shown in Table 1.

Comparative Example 8 Examples 43-49 were repeated except that carbon black C was removed from the ceramic formulation.

The wear resistance, Vickers hardness, bending strength, porosity, coefficient of thermal expansion, thermal conductivity, and fracture toughness of the water jet nozzle were measured and found to be as shown in Table 1.

Further, the life of the water jet nozzle is about 1 to 7
The measurement was carried out in the same manner as above, and it was as shown in Table 1.

Comparative Example 9 Examples 50-56 were repeated except that carbon black C was removed from the ceramic formulation.

The wear resistance, Vickers hardness, bending strength, porosity, coefficient of thermal expansion, thermal conductivity, and fracture toughness of the water jet nozzle were measured and found to be as shown in Table 1.

Further, the life of the water jet nozzle is about 1 to 7
The measurement was carried out in the same manner as above, and it was as shown in Table 1.

Comparative Example 10 Examples 57-63 were repeated except that the carbon black C was removed from the ceramic formulation.

The wear resistance, Vickers hardness, bending strength, porosity, coefficient of thermal expansion, thermal conductivity, and fracture toughness of the water jet nozzle were measured and found to be as shown in Table 1.

Further, the life of the water jet nozzle is about 1 to 7
The measurement was carried out in the same manner as above, and it was as shown in Table 1.

Comparative Example 11 Examples 64-70 were repeated except that carbon black C was removed from the ceramic formulation.

The wear resistance, Vickers hardness, bending strength, porosity, coefficient of thermal expansion, thermal conductivity, and fracture toughness of the water jet nozzle were measured and found to be as shown in Table 1.

Further, the life of the water jet nozzle is about 1 to 7
The measurement was carried out in the same manner as above, and it was as shown in Table 1.

Comparative Example 12 Examples 71-77 were repeated except that chromium Cr and carbon black C were removed from the ceramic formulation.

The wear resistance, Vickers hardness, bending strength, porosity, coefficient of thermal expansion, thermal conductivity and fracture toughness of the water jet nozzle were measured, and the results are shown in Table 2.

Further, the life of the water jet nozzle is about 1 to 7
When measured in the same manner as in, the results are shown in Table 2.

Comparative Example 13 Examples 78-84 were repeated except that chromium Cr and carbon black C were removed from the ceramic formulation.

The wear resistance, Vickers hardness, bending strength, porosity, coefficient of thermal expansion, thermal conductivity and fracture toughness of the water jet nozzle were measured, and the results are shown in Table 2.

Further, the life of the water jet nozzle is about 1 to 7
When measured in the same manner as in, the results are shown in Table 2.

Comparative Example 14 Examples 85-91 were repeated except that chromium Cr and carbon black C were removed from the ceramic formulation.

The wear resistance, Vickers hardness, bending strength, porosity, coefficient of thermal expansion, thermal conductivity and fracture toughness of the water jet nozzle were measured, and the results are shown in Table 2.

Further, the life of the water jet nozzle is about 1 to 7
When measured in the same manner as in, the results are shown in Table 2.

Comparative Example 15 Examples 92-98 were repeated except that chromium Cr and carbon black C were removed from the ceramic formulation.

The wear resistance, Vickers hardness, bending strength, porosity, coefficient of thermal expansion, thermal conductivity and fracture toughness of the water jet nozzle were measured, and the results are shown in Table 2.

Further, the life of the water jet nozzle is about 1 to 7
When measured in the same manner as in, the results are shown in Table 2.

Comparative Example 16 Examples 99-105 were repeated except that chromium Cr and carbon black C were removed from the ceramic formulation.

The wear resistance, Vickers hardness, bending strength, porosity, coefficient of thermal expansion, thermal conductivity and fracture toughness of the water jet nozzle were measured, and the results are shown in Table 2.

Further, the life of the water jet nozzle is about 1 to 7
When measured in the same manner as in, the results are shown in Table 2.

Comparative Example 17 Examples 71-77 were repeated except that the carbon black C was removed from the ceramic formulation.

The wear resistance, Vickers hardness, bending strength, porosity, coefficient of thermal expansion, thermal conductivity and fracture toughness of the water jet nozzle were measured, and the results are shown in Table 2.

Further, the life of the water jet nozzle is about 1 to 7
When measured in the same manner as in, the results are shown in Table 2.

Comparative Example 18 Examples 78-84 were repeated except that carbon black C was removed from the ceramic formulation.

The wear resistance, Vickers hardness, bending strength, porosity, coefficient of thermal expansion, thermal conductivity and fracture toughness of the water jet nozzle were measured, and the results are shown in Table 2.

Further, the life of the water jet nozzle is about 1 to 7
When measured in the same manner as in, the results are shown in Table 2.

Comparative Example 19 Examples 85-91 were repeated except that carbon black C was removed from the ceramic formulation.

The wear resistance, Vickers hardness, bending strength, porosity, coefficient of thermal expansion, thermal conductivity and fracture toughness of the water jet nozzle were measured, and the results are shown in Table 2.

Further, the life of the water jet nozzle is about 1 to 7
When measured in the same manner as in, the results are shown in Table 2.

Comparative Example 20 Examples 92-98 were repeated except that carbon black C was removed from the ceramic formulation.

The wear resistance, Vickers hardness, bending strength, porosity, coefficient of thermal expansion, thermal conductivity and fracture toughness of the water jet nozzle were measured, and the results are shown in Table 2.

Further, the life of the water jet nozzle is about 1 to 7
When measured in the same manner as in, the results are shown in Table 2.

Comparative Example 21 Examples 99-105 were repeated except that carbon black C was removed from the ceramic formulation.

The wear resistance, Vickers hardness, bending strength, porosity, coefficient of thermal expansion, thermal conductivity and fracture toughness of the water jet nozzle were measured, and the results are shown in Table 2.

Further, the life of the water jet nozzle is about 1 to 7
When measured in the same manner as in, the results are shown in Table 2.

Comparative Example 22 Comparative Example 1 above was repeated except that the ceramic formulation was silicon nitride Si ₃ N ₄ .

The wear resistance, Vickers hardness, bending strength, porosity, coefficient of thermal expansion, thermal conductivity and fracture toughness of the water jet nozzle were measured, and the results are shown in Table 3.

The life of the water jet nozzle was measured in the same manner as in Comparative Example 1 and then Examples 1 to 7, and was as shown in Table 3.

Comparative Example 23 Comparative Example 1 above was repeated except that the ceramic formulation was silicon carbide SiC.

The wear resistance, Vickers hardness, bending strength, porosity, coefficient of thermal expansion, thermal conductivity and fracture toughness of the water jet nozzle were measured, and the results are shown in Table 3.

The life of the water jet nozzle was measured in the same manner as in Comparative Example 1 and then Examples 1 to 7, and was as shown in Table 3.

As is clear from a comparison between Examples 1 to 105 and Comparative Examples 1 to 23 described above, according to the present invention, at least one metal selected from chromium Cr, nickel Ni, and molybdenum Mo which are transition metals is used. A nozzle for water jet is formed as a whole by a titanium boride ceramics sintered body in which a matrix layer of a mixed solid solution of boride and titanium carbide is arranged between titanium boride particles and has a porosity of 5% or less. As a result, it is possible to sufficiently suppress the wear of the nozzle hole due to the jetting of the pressurized water, and it is possible to greatly extend the life of the nozzle hole. In the examples, the transition metals are all chromium Cr.
, But other nickel Ni, molybdenum
The same effect was obtained with Mo.

(3) Effects of the Invention As is apparent from the above, the water jet nozzle according to the present invention is for a water jet that jets the pressurized water while being held by a nozzle holder attached to the tip of the supply pipe of the pressurized water. A nozzle, in which a matrix layer formed by mixing and solid-dissolving a boride of at least one metal selected from transition metals such as chromium Cr, nickel Ni, and molybdenum Mo and titanium carbide is disposed between titanium boride particles. And the titanium boride ceramics sintered body having a porosity of 5% or less is formed entirely, (i) it has the effect of sufficiently suppressing the wear of the nozzle hole portion due to pressurized water, and (ii) ) It has the effect of extending the service life.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a water jet nozzle according to the present invention, FIG. 2 is a sectional view showing a usage state of the embodiment of FIG. 1, and FIG. 3 is an enlarged view showing the embodiment of FIG. FIG. 4 is a sectional view, FIG. 4 is an optical microscope photograph showing the texture of the surface of the polishing treatment of FIG. 1, and FIG. 5 is a scanning electron microscope photograph showing the texture of the fracture surface of FIG. 1 embodiment. Is an optical micrograph showing the texture of the etched surface of FIG. 1 embodiment, FIG. 7 is a scanning electron micrograph showing the texture of the etched surface of FIG. 1, and FIG. 8 is FIG. A scanning electron micrograph showing the texture of the polished surface of the example, FIG. 9 is a copy of FIG. 8, and FIG. 10 is an EPMA analysis of the texture of the polished surface of the example of FIG. 1, that is, an electron probe. X-ray intensity distribution chart showing the results of microanalysis, FIG. 11 (a) is FIG. 1 Example EPMA analysis of the texture of the polished nozzle hole surface, that is, an X-ray intensity distribution photograph showing the results of electron probe microanalysis, FIG. 11 (b) is an EPMA analysis of the texture of the polished surface of the embodiment of FIG. An X-ray intensity distribution photograph showing the results of electron probe microanalysis, FIG. 11 (c) is a copy of FIG. 11 (a) and (b), and FIG. 12 is the X of the embodiment of FIG. FIG. 13 is a scanning electron micrograph showing the structure of the fracture surface of the water jet nozzle shown as Comparative Example 1, which is a graph showing the results of line diffraction analysis. 10 …… Water jet nozzle 11 …… Nozzle hole analysis 12 …… Locking end face 13 …… Fixed cross section 14 …… Nozzle holding part 14 A …… Central hole 14 B …… Locking step part 15 …… Fixing member 15 A …… Fixed end face 16 …… Reinforcing tool 20 …… Titanium boride particles 21 …… Grain boundary phase 30 …… Matrix layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Junichi Matsushita 1-111 Tsukisan-cho, Minato-ku, Nagoya-shi, Aichi Prefecture

Claims (1)

[Claims] 1. A water jet nozzle for ejecting pressurized water in a state of being held by a nozzle holder attached to a tip end portion of a pressurized water supply pipe, wherein transition metals such as chromium Cr, nickel Ni and molybdenum Mo are used. A titanium boride ceramics sintered body in which a matrix layer in which a boride of at least one selected metal and titanium carbide is mixed and solid-dissolved is arranged between the titanium boride particles and has a porosity of 5% or less. A water jet nozzle characterized in that the whole is formed by.